From: pjb@... (Pascal J. Bourguignon)
Date: 2009-01-14T19:44:11+09:00
Subject: Re: functional programming

Mike Gold <mike.gold.4433@gmail.com> writes:

> Pascal J. Bourguignon wrote:
>> Mike Gold <mike.gold.4433@gmail.com> writes:
>> 
>>> Why is func.call() or func[] or func.() "very useful" compared to
>>> func()?  As I mentioned, in every case I've found it to be a
>>> hassle, for the reasons previously stated.
>> 
>> The reason is because Ruby is a lisp-2.  The same name can be used to
>> designate both a method and a variable.  So you need two syntaxes, to
>> make reference to the method of a name, or to the variable. 
>
> No, that's not the reason.  It is because Ruby allows method invocation 
> without parens.  Therefore parens cannot be used to unambiguously 
> "dereference" a function.  

It wouldn't matter if we had not to distinguish calling a named
function from calling a function stored in a variable.

So we could say that we're in violent agreement.


> The case in point is Python,
>
> class X:
>   def f(self):
>     return "foo"
>
> x = X()
> g = x.f
> g() #=> "foo"
>
> triple = lambda z: 3*z
> triple(2) #=> 6
>
> We all know the Ruby version, but just for good measure --
>
> class X
>   def f
>     "foo"
>   end
> end
>
> x = X.new
> g = x.method(:f)
> g.call #=> "foo"
>
> triple = lambda { |z| 3*z }
> triple.call(2) #=> 6

-- 
__Pascal Bourguignon__